Aircraft and propulsion (gas turbine engines) power system architecture has been heading for major changes. A dominant trend in advanced aircraft power systems is increasing use of electric power to drive aircraft and propulsion subsystems that, in conventional aircraft, have been driven by a combination of mechanical, electrical, hydraulic, and pneumatic systems.
A trend is to replace more engine-driven mechanical, hydraulic, and pneumatic loads with electrical loads to enhance system performance and reliability. More particularly, electrical subsystems may require lower engine power and operate at higher efficiency relative to conventional mechanical, hydraulic, and pneumatic systems, but they also can be used only as needed.